> The submodule merge code is being transitioned away from > add_submodule_odb() to repo_submodule_init(), and the latter does not > support submodules that have their .git directories in the worktree > (instead of in .git/modules). Migrate the test code by calling > absorbgitdirs wherever necessary to place the .git directories of > submodules in .git/modules of the superproject. Upon further work, there seems to be quite a lot of test code to migrate, and it might be easier instead to add support for unabsorbed submodules to repo_submodule_init() (say, following what open_submodule() in submodule.c does). Feel free to comment on this or other aspects of the patch set, and in the meantime, I'll investigate that.
